1. Field of the Invention
The present invention relates to an exhaust flow director and catalyst mount for internal combustion engine which serves not only as an exhaust manifold for collecting exhaust gases exiting the cylinder head of an engine, but also for a directly mounted exhaust after treatment catalyst.
2. Disclosure Information
Exhaust manifolds or exhaust headers have been used on multi-cylinder reciprocating internal combustion engines for many years. Known exhaust manifolds or headers simply collect the gases passing from the cylinder head exhaust ports and convey the gases to an exhaust pipe. Typically, the catalyst is contained downstream of the exhaust pipe.
Although close coupled catalysts are known in the automotive world, such catalysts are generally not mounted with their inlets in a coplanar relationship with the exhaust runners. As a result, the flow velocities across the catalyst are not uniform and often are diminished because of flow and thermal losses within the exhaust manifold. Accordingly, U.S. Pat. No. 6,840,039 discloses an exhaust manifold including a converging-diverging section upstream from a catalyst. Apparently, an avowed purpose of the converging-diverging section is to reduce exhaust heat, but this will cause the decided disadvantage of increasing catalyst light-off time.
An exhaust flow director and catalyst mount according to the present invention provides superior flow direction for the individual flows entering exhaust collector chamber from the manifold runners, so as to provide uniform velocity distribution and also uniform temperature distribution to the front face of the catalyst which is mounted directly to the outlet flange, while preserving the exhaust heat. This promotes faster catalyst light-off.